RE: send data over uart without losing connection

Christopher — Mon, 21 Mar 2016 19:29:11 GMT

Many users already asked for you problem (see here some search results). Here is a Nordic's answer, and here is another one.

As described here, you can send up to 20 bytes in each notification packets. Depending on the SoftDevice you use, you can send one or more BLE packets per connection interval.

To send a large chunk of data, you have to use the BLE_EVT_TX_COMPLETE event. A simple solution consist of sending as many bytes as you can until you get the BLE_ERROR_NO_TX_BUFFERS, and then wait for the BLE_EVT_TX_COMPLETE event to send again as much as data as you can. Another solution consist of tracking the number of available TX buffers/packets (using p_ble_evt->evt.common_evt.params.tx_complete.count).

RE: send data over uart without losing connection

awneil — Mon, 21 Mar 2016 13:14:57 GMT

You need a buffer (or "queue") to hold the data that's awaiting transmission.